There are numerous surgical, cosmetic, therapeutic and dermatological procedures that involve maneuvering an area of skin and it is often beneficial to create tension in a skin area or a body surface where a particular procedure is performed. By way of example, hair transplantation is one of those procedures and it typically involves harvesting donor hair grafts from the “donor areas,” for example, side and back fringe areas of the patient's scalp, or other body surfaces, and implanting them in a bald area (“recipient area”). Hair transplantation is a very labor-intensive and complex procedure that requires skill and precision. Various techniques were developed over the years for harvesting donor hair grafts. One such technique involves excising a strip of skin from the back area of the scalp and then dissecting the strip under a microscope to isolate individual hair follicular units for later implantation into the recipient area. This technique suffers numerous disadvantages, including being very time consuming, tedious, expensive, and requiring suturing and resulting scarring. Another technique called Follicular Unit Extraction (“FUE”) allows harvest of individual follicular units without a need to cut a strip of tissue from the patient's scalp.
An FUE method for harvesting follicular units allows for individual follicular units to be harvested directly from the donor area by utilizing a hollow punch having a cutting edge and an interior lumen with a diameter of, for example, 1 mm. The punch is used to make a small circular incision in the skin around the follicular unit. Thereafter, the follicular unit is removed, e.g., using forceps, for subsequent implantation into a recipient site with a specially devised insertion needle. FUE procedure avoids scarring associated with cutting a strip of scalp, reduces patient's discomfort, and reduces recovery time, however, it is a laborious procedure, take a long time to perform and it requires a high degree of technical skill. During such procedures, typically manually performed by a physician, in order to tension a skin surface in the area of hair harvesting or implantation, pressure is typically applied adjacent the target location using two fingers. Similar skin tensioning techniques are used in various cosmetic and dermatological procedures other than hair transplantation.
One automated system for harvesting follicular units from a body surface is disclosed in U.S. Patent Publication 2007/0078466. In one embodiment a skin tensioner in the form of two tines presses against a skin surface to thereby tension the skin. Another example of a skin tensioner is described in commonly assigned U.S. Patent Publication Number US2010/0191253.